Green neon tetra care guide
Also called: False neon tetra, Green neon
The green neon tetra is a very small, peaceful schooling fish with a blue-green stripe and only a faint trace of red. It is a lovely nano fish for soft, acidic planted tanks, but it needs a group of 10 or more and stable blackwater-style conditions.
Green neon tetras need a tank of at least 10 gallons (38 L), a group of 10 or more, and water at 24–27°C (75–81°F) with a pH of 5–6.5. They grow to about 2.5 cm (1 in) and are peaceful.
Plan a tank with green neon tetrasSee all tank mates
Green neon tetra quick facts
| Scientific name | Paracheirodon simulans |
|---|---|
| Family | Acestrorhamphidae |
| Origin | Upper Rio Negro and Orinoco basins in Brazil, Colombia and Venezuela (mostly wild-caught) |
| Adult size | 2.5 cm (1 in) |
| Minimum tank | 10 gallons (38 L), at least 45 cm (18 in) long |
| Temperature | 24–27°C (75–81°F) |
| pH | 5–6.5 |
| Hardness (GH) | 1–6 dGH |
| Group size | 10 or more (schooling fish) |
| Temperament | Peaceful |
| Swims at | Middle |
| Diet | Omnivore |
| Care level | Moderate |
| Lifespan | 2–4 years |
| Safe with shrimp? | Mostly (eats baby shrimp) |
| Safe with plants? | Yes |
Tank setup
A planted tank of at least 10 gallons (38 L) and 18 in (45 cm) long works for a group of 10. Dim light, floating plants, leaf litter and a dark substrate help these shy fish settle. A sponge filter or other gentle flow suits them best.
How many green neon tetras in a tank?
The smallest common tank that suits green neon tetras is a 10 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Green neon tetras (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | 10–27 |
| 15 gallon | 10–41 |
| 20 gallon | 10–55 |
| 20 gallon long | 10–55 |
| 29 gallon | 10–79 |
| 40 gallon | 10–110 |
| 55 gallon | 10–151 |
| 75 gallon | 10–206 |
| 125 gallon | 10–344 |
What you need for green neon tetras
Sized for a 10 gallon tank, the smallest common size that suits a group of 10 green neon tetras. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 10 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Adjustable heater, 50 W (opens Amazon in a new tab)Holds about 78 °F (25.5 °C) in a room at 65 °F (18 °C). How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Hang-on-back filter rated 40–60 GPH (opens Amazon in a new tab)Community tank: 4–6 times the tank volume per hour. How to choose
- About 25 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 20 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for green neon tetras
- Micro pellets or flakes for small fish (opens Amazon in a new tab)Small enough for tetras, rasboras and other nano fish.
- Indian almond leaves (opens Amazon in a new tab)Release tannins that soft-water fish like bettas and rams enjoy.
Product links go to Amazon search results. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Disclosure.
Water parameters
They come from soft, acidic blackwater, so aim for 24–27 °C (75–81 °F), pH 5.0–6.5 and 1–6 dGH. Some fish adapt to neutral water, but most green neons are wild-caught and do best in soft, acidic conditions. Keep the water clean and steady with regular small water changes.
Best tank mates for green neon tetras
These popular species share green neon tetras' water needs and temperament. See the full list of 59 good matches.
Cherry shrimp
3 cm (1.2 in) · 20–27°C (68–81°F)
Dwarf gourami
7.5 cm (3 in) · 24–28°C (75–82°F)
Bristlenose pleco
12 cm (4.7 in) · 22–26°C (72–79°F)
Bronze corydoras
7 cm (2.8 in) · 21–26°C (70–79°F)
African dwarf frog
3.5 cm (1.4 in) · 22–26°C (72–79°F)
Amano shrimp
4.5 cm (1.8 in) · 20–27°C (68–81°F)
Chili rasbora
2 cm (0.8 in) · 22–27°C (72–81°F)
Ember tetra
2 cm (0.8 in) · 23–28°C (73–82°F)
Avoid keeping green neon tetras with
- Angelfish: Angelfish can eat green neon tetras: they're small enough to fit in its mouth once it's grown.
- Common goldfish: They need different temperatures: Green neon tetra 24–27°C (75–81°F), common goldfish 15–22°C (59–72°F).
- Fancy goldfish: They need different temperatures: Green neon tetra 24–27°C (75–81°F), fancy goldfish 18–23°C (64–73°F).
- Oscar: Oscar can eat green neon tetras: they're small enough to fit in its mouth once it's grown.
- Bala shark: Bala shark can eat green neon tetras: they're small enough to fit in its mouth once it's grown.
- Blood parrot cichlid: Blood parrot cichlid can eat green neon tetras: they're small enough to fit in its mouth once it's grown.
Feeding
An omnivore with a very small mouth. Feed crushed flakes, nano pellets or powdered foods, and add live or frozen baby brine shrimp, daphnia and cyclops several times a week. Small, frequent meals keep this tiny fish in good shape.
Behavior
Peaceful and shy, it swims in a tight group in the middle of the tank. Its small size makes it a poor match for boisterous or large fish. Tiny tetras, pencilfish, small corydoras and dwarf shrimp are better company, and in a group of 10 or more it becomes much bolder.
Breeding
Rarely bred in home aquariums, and not bred commercially on any real scale. It scatters eggs, and either a single pair or a small conditioned group can be used. A dark tank with very soft, acidic water, fine plants or mesh, and removing the adults after spawning gives the best chance. The eggs and fry are sensitive to light.
Tips from experienced keepers
- Keep at least 10. This tiny fish is more nervous than the common neon tetra.
- Use floating plants or tannin-stained water to dim the light. They color up and hide less.
- Choose small, calm tank mates such as pencilfish, ember tetras or pygmy corydoras.
- Acclimate slowly. Most are wild-caught and react badly to sudden changes in water chemistry.
Frequently asked questions
What is the difference between a green neon tetra and a neon tetra?
The green neon is smaller, about 1 in (2.5 cm), with a blue-green stripe and only a faint trace of red low on the body. It also needs softer, more acidic water than the farm-bred neon tetra.
How many green neon tetras should be kept together?
Keep at least 10. Larger groups are calmer and swim more openly instead of hiding.
Can green neon tetras live in a 10 gallon tank?
Yes. A well-planted 10 gallon (38 L) tank can hold a group of about 10, as long as the water is soft and stable and the tank mates are tiny and peaceful.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.